Method of picking weft yarns in shuttleless looms

ABSTRACT

Method and apparatus for inserting weft threads on a shuttleless loom by picking up the weft thread and carrying it at least through part of the length of the shed by either mechanical means or a pressure fluid flow and subsequently contacting the front part of the weft thread with a flow of a pressurized fluid to carry it through the remaining length of the shed in a selectively controlled and directed manner.

United States Patent 1 1 1.111 3,821,972 Svaty et al. July 2, 1974 [54]METHOD OF PICKING WEFI YARNS IN 3,140,636 7/1964 Vincent 139/127 P3,229,725 1/1966 Saito 139/127 P SHUTTLELESS LPOMS 3,482,606 12/1969Mizuno et a1. 139/127 P 1 Inventors: a imir Svaty; Jiri Libansky, both3,705,608 12/1972 Vermuelen 139/127 P of Liberec. Czechoslovakia [73]Assignee: Elitex Zavody textilniho I strojirenstvi, generalnireditelstvi, Prlma'y Jaudon ff Liberec, Czechoslovakia Attorney, Agent,or zr murray Scha er [22] Filed: Sept. 16, 1971 [21] App]. No.: 181,154ABSTRACT Foreign Application Priority Data Method and apparatus forinserting weft threads on a Sept. 18, I970 Czechoslovakia 6368-70shuttleless loom by picking up the weft thread and carrying it at leastthrough part of the length of the [52] US. Cl. 139/127 P shed by eithermechanical means or a pressure fluid [51] Int. Cl D03d 47/30 flow andsubsequently contacting the front part of the [58] Field of Search139/122 R, 127 P weft thread with a flow of a pressurized fluid to carryit through the remaining length of the shed in a selec- [56] ReferencesCited tively controlled and directed manner. UNITED STATES PATENTS3,139,118 6/1964 Svaty et a1 139/127 P 12 Claims, 5 Drawing FiguresPATENTEBJUI. 2 I974 SHEET 1 BF 4 INVENTOR S ATTO R N EY PATENTEU JUL 2I974 SHEET H 0F 4 r 1 METHOD OF PICKING WEFI YARNS IN SHUTTLELESS LOOMSBACKGROUND OF THE INVENTION This invention relates to a method andapparatus for inserting weft threads into the shed formed on ashuttleless loom. More particularly, the invention relates to amethod'and apparatus for inserting weft threads in which initialinsertion into the shed is achieved by either a primary pressure fluidflow, such as air flow or rotary feeding rollers which cause the threadto move into a guiding channel formed by a comb having a plurality ofplates and openings and then to be subsequently carried through thechannel and the shed by a plurality of successive pressure fluid streamsin a selectively controlled and directed manner.

In shuttleless weaving machines or looms, the thread end is picked andthrown through the shed with its end free. In those looms employing apneumatic nozzle to pick up the weft thread, a flow of compressed air isemployed to carry the weft thread through the shed by the effect of theair flow. The air leaves a nozzle located on one side of the machine inan abrupt manner and passes through a comb having a plurality of platesand openings inserted into the shed before the weft thread is picked up.The individual plates and openings of the comb form a guiding channelfor the weft, as well as for the compressed air flowing from the nozzle,minimizing loss of air due to dissipation. However, with such anarrangement, the pressure and continuity of the air or other suitablecarrying fluid is diminished as the distance from the nozzle increases.Consequently, the front part of the weft inserted into the shed issubjected to a fluid flow of continuously diminishing velocity as itiscarried through the shed while the rear part continues to besurrounded by a high velocity fluid flow from the nozzle. Therefore, theentraining effect of the fluid on the weft, determined by the differencein relative velocities of the fluid flow, produces a driving force onthe rear part of the weft which is higher than that acting upon thefront part. Since the strut strength of the weft, that is, the stiffnessalong its axial dimension, sufficient to resist longitudinal thrust, isneglibible, internal compensation of these forces within the threadcannot be achieved and the rear part of the weft is accelerated morethan the front part. Consequently, the picked weft thread or yarn iscaused to have a wave shape imparted to it during flight. This oftenresults in the front part of the weft being caught up against the warpthreads on the plates of the guiding comb. Incorrect picking, resultingfrom this condition, very often causes the formation of loops on theweft thread as well as short pickings and other weaving failures.

These disadvantages of weft insertion or picking are partially removedby diminishing the velocity of the fluid flow during the course ofpicking the weft. However, in such a case, the rear part of the weft isaccelerated by a continuously diminishing force, while the front part ofthe weft'continues to be subjected to the velocity drop of the fluidflow. This results in reduction of the mean velocity of the packed weftthread and sists of a plurality of nozzles for guiding a secondary fluidor air flow, the nozzle being arranged transversely to the warp threadsand having on their surface a row of saw-toothed means which spread thewarp threads after opening the shed and thus partially penetrate theshed so that the pressure fluidflow excaping from these secondarynozzles assists in the weft thread insertion. Another known systemconsists of spouts to guide a secondary pressure air flow and in whichthe spouts are equipped with a set of obliquely mounted and chamberednozzles for easy spreading of the warp threads. In this system thenozzles are usually concentrated at the side opposite to the main pickupnozzle which commits the primary pressure fluid. In addition, some knownsystems utilize a set of semi-circular rotary nozzles which arechambered at their ends to facilitate penetrating the warp threads, thenozzles being arranged below the warp on pivots which simultaneouslysupply the secondary pressure fluid and includes means attached to thenozzles to impart to them a reversing rotary motion synchronously withthe drive of the machine, thus opening a passage for the fluid into thenozzles.

A disadvantage of these devices resides in the fact v ondary carryingfluid flow escaping therefrom is relacauses a drop in maximum operatingspeed and reduced output of the loom.

To overcome these disadvantages, various types of pneumatic systems havebeen developed to contribute to a correct weft picking. For example, onesystem contively small. It is further suppressed by the flow of thesecondary carrying pressure fluid being directed into a space which islimited only by the opened warp threads. Thus, the dissipation of theflows is immediate. Each penetration of the rotary nozzles, as well asthe other nozzles, of the afore-mentioned pneumatic systems into thewarp thread system manifests itself by leaving a visible, undesiredstripe in the fabric.

A common disadvantage of all pneumatic weft inserting systems such asthose mentioned above resides in the fact that the weft is not actedupon by the flow of the secondary carrying pressure medium in such amanner as to be continuously drawn into the shed by its front part; butrather the weft is acted upon throughout the overall length by a systemof plural, longitudinally arranged nozzles into which the secondarypressure fluid is fed either periodically, simultaneously orcontinuously. This manner of distributing the secondary carryingpressure fluid is disadvantageous since it does not supply the neededair and does not insure that the weft, upon its advancement through theshed, will not take upa wave shape and will not be caught by the warpthreads or the plates of the guiding comb. There exists, therefore, aneed for an improved method and apparatus which overcomes thesedisadvantages.

It is, therefore, a primary object of this invention to provide a methodfor inserting weft threads in a shed formedon a shuttleless loom bycontacting a weft thread with means to pick it up and carry it throughat least part of the length of the shed and then contacting the frontpart of the weft thread with a plurality of successive pressure fluidflows and carrying the weft thread in a selectively controlled anddirected manner through the remaining portion of the length of the shed.

It is another object of the invention to provide a method for insertingweft threads wherein a weft thread is picked up and carried through atleast part of the length of the shed by a primary pressure fluid andthen by successive secondary pressure fluid flows.

It is still another object of the invention to provide a method forinserting weft threads wherein a weft thread is picked up and carriedthrough at least part of the length of the shed by rotating feed rollersand then by successive pressure fluid flows.

It is still a further object of the invention to provide a method forinserting weft threads wherein a weft thread is carried into a guidingchannel formed by a comb which is periodically merged into the shed.

It is still a further object of the invention to provide apparatus forinserting weft threads in a shed formed on a shuttleless loom having abatten, a comb having a plurality of plates and openings supported onthe batten and forming a guiding channel for the weft thread uponperiodic merging of the comb in the shed, and including a plurality ofmeans supported on said batten for diverting a plurality of pressurefluid flows into the guiding channel and means to successively activateand deactivate the flows of pressure fluid in a selectively controlledand directed manner.

It is still a further object of the invention to provide an apparatusfor inserting weft threads wherein nozzles are mounted on the batten ofa loom and directed to guide a plurality of pressure fluid flowsobliquely into a guiding channel formed by a comb which is periodicallyimmerged in the shed.

It is still another object of the invention to provide apparatus forinserting weft threads which includes sensing elements located in theplates of the guiding comb to selectively control activation anddeactivation of nozzles which direct a plurality of pressure fluid flowsin a guiding channel formed by the comb.

It is still another object of the invention to provide apparatus forinserting weft threads which includes a distributor for a pressure fluidconnected to nozzles mounted on the batten of a loom and adapted tosuccessively and selectively direct a plurality of pressure fluid flowsin a guiding channel formed by a guiding comb.

SUMMARY OF THE INVENTION According to the present invention, a systemfor weft insertion is provided wherein the forces acting upon the weftas driving forces are at a maximum at the front part of the weft andgradually disappear in the direction towards its rear part so that theweft is straightened and pulled during its picking so that the frontpart of the weft picked by a primary system is taken over in the courseof its movement through the shed by secondary flows of a pressurecarrying fluid which are selectively controlled to operate successivelyand are oriented substantially longitudinally in the direction ofmovement of the weft through the shed.

According to the present invention a method and apparatus provided bywhich the weft thread is picked up and caused to be carried through aportion of the shed by a primary device and through the remainingportion of the shed by a plurality of successive, pressurized fluid flowstreams in a selected and predetermined manner acting on the front endof the thread.

Preferably, the secondary flow streams are directed through the combs of.the shed and act on the weft as the weft is guided through the channelformed by the combs.

Additional advantages and features of the invention as well as fulldetails will be apparent from the following description thereof which isto be taken in conjunction with the accompanying drawings.

THE DRAWINGS In the drawings:

FIG. 1 is a schematic, cross-sectional view in elevation illustrating abatten on a shuttleless loom and showing the comb and a nozzle forsupplying a secondary pressure fluid, both being mounted along with thereed on the batten in accordance with the present invention;

FIG. 2 is a schematic, cross-sectional view in elevation of anembodiment of a distributor for the secondary pressure fluid;

FIG. 3 is a schematic, cross-sectional plan view of the distributorshown in FIG. 2 and taken across line 22 thereof; and

FIG. 4 is a schematic, cross-sectional view in elevation of theembodiment shown in FIG. 1 employing individual sensing means and valvesto activate and deactivate the secondary pressure fluid, and

FIG. 5 is a perspective view of weaving shed with a plurality of jetnozzles schematically shown.

- It is to be understood that the drawings and description set forthhereinafter give only those details of a loom which are necessary forunderstanding the present invention. It will be obvious that certainwell known details are omitted. Reference is directed to conventionallooms, well known texts and literature and particularly to theshuttleless looms disclosed in pending U.S. Patent applications, Ser.Nos. 79,035 and 79,478 filedon Oct. 8, and 9, 1970, respectively, by V.Svaty and which are incorporated intothe present case.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In accordance with theinvention there is provided a method for inserting weft threads in theshed formed on a shuttleless loom which comprises contacting a weftthread with means for picking up and carrying the thread through atleast part of the length of the shed in a substantially longitudinaldirection and then contacting the front part of the thread with aplurality of successive pressure fluid flows and carrying the weftthread in a selectively controlled and directed manner in asubstantially longitudinal direction through the remaining portion ofthe length of the shed.

Referring now to FIG. I, apparatus for accomplishing the methodcomprises a batten l which is fastened by means of screws or bolts 2 onthe slay arms 3 of a shuttleless loom in a known manner. The battenswings on a batten shaft 4 and is provided with longitudinal grooves 5and 6. Groove 5 supports a reed 7 which is fastened therein by bolts 8.Groove 6 supports a guiding comb 9 having a plurality of separateplates, one being shown at 10 which form openings. The plates constitutea continuous channel 11 which is interrupted only by the gaps betweenthe separate plates and which are penetrated by warp threads 12 as soonas the guiding comb 9 is immerged into the shed 13 when the batten 1moves from front dead center to rear dead center.

The supply of the weft by a primary pneumatic fluid source and theoperation of the loom per se are set forth in the aforementionedcopending applications to which reference can be made. In lieu of apneumatic primary picking and throwing system, shuttleless looms haveemployed contrarotating roller mechanisms which pick up and throw theweft. These also are well known and suitably described in knownliterature.

Pneumatic nozzles 14 are located serially from one end of channel 11 tothe other in the space between the reed 7 and the guiding comb 9 and areeach oriented obliquely with respect to the guiding channel 11. Each ofthe nozzles 14 are constituted by openings '14 in tubes 15 to supply asecondary carrying pressure fluid, such as air, serially along thechannel 11. The tubes 15 are closed at their upper ends 16 and arefastened in any suitable manner into the batten 1, each tube beingconnected by a flexible hose 17 to the separate outlets 18, 18a, 18c,etc. of a distributor 19 which functions to distributed the secondarycarrying pressure fluid from a source of fluid under pressure. Thedistributor has as many outlets 18, etc. as the number of nozzles 14arranged along the length of the channel 11.

The distributor 19, which is situated aside batten l, is constituted inthe embodiment shown by a pressure vessel having a hollow interior 20covered by a lid 21. A rotary slide valve 22 is disposed in the interior20. Rotary motion is imparted in the slide valve through shaft 23, whichis synchronized with the conventional main shaft of the weaving machinevia a suitable gear train. The rotary slide valve 22 is provided with abypass opening 24 which is of sufficient size to cover at least twooutlets 18, 18a, etc. situated beside each other in the distributor 19.i

For supplying the secondary carrying pressure fluid from a source to thedistributor 19, an extension conduit 25 mounted on the lid 21 ofdistributor 19 is provided. The source of pressure may be a pump or acontainer of compressed air. Preferably it is provided with pressurecontrol means by which tee pressure flow may be regulated as to volumeand degree of pressure. ln some embodiments, it may be helpful toregulate the degree of pressure successively to each of the seriallyarranged nozzles 14. The embodiment shown, thus far, operatessynchronously with the loom being responsive to the main drive shaft viathe connecting gear train.

The distributor 19 can be replaced by a system of valves for each or forone or more of the nozzles. The operation of the valves is controlled byvarious detecting elements which would respond not to the main loomdrive but to the movement of the weft 26 in the shed 13. The detectingelements can be sensors of any known construction. For example,pneumatic, capacitor, photoelectric or similar types which emit impulsescorresponding to the presence and/or movement of weft 26. The impulsesmay be supplied to the separate valves which secure the serial operationof the appropriate nozzles 14 distributed at suitable distances alongthe guiding channel 11 in the guiding comb 9. The nozzles may also actsimultaneously as weft stop motions. A schematic showing such a systemis seen in FIG. 4, in which a sensor 27 is placed within the comb plate10 and is connected to a transducer or similar device 28 which in turnproduces a signal impulse responsive to the sensing by sensor 27 of theweft 26. The transducer signal impulse is transmitted to a valve 29operated by a solenoid or other convenient device to pass a burst of airfrom the source 30 into the appropriate conduit, such as 18. Thepressure regulating or control valve 31 may be inserted between thesource 30 and each of the valves 29. This latter valve 31 is alsoconnected to the sensors 27 so that the degree of pressure may be variedin accordance with the nozzle 14. The sensors 27, the pressure controlvalve and other features may also be used with the distributor systemshown in FIGS. 2 and 3. The transducer 28 amplifies and produces asignal impulse and controls the length and timing of the signal so thata selective one or more of the valves 29 are open to let air pass intothe nozzles 14 in a selected and predetermined manner.

The devices described operate as follows:

At the moment at which, by any of the known methods, weft 26 is abruptlyejected into the guiding channel 11 in the guiding comb 9, such as bymeans of an air nozzle (not shown) for the primary carrying pressurefluid, or with rotating feeding rollers or any other similar device, thedistributor port 18 in the distributor 19 is opened by means of therotary slide valve 22. The carrying pressure fluid passes through tubeor hose 17 into the nozzle 14, which is arranged at immediate proximityof the primary weft picking system. Thus, the front end of weft 26 issurrounded by a secondary carrying stream which entrains the front partof weft 26 and carries it longitudinally to the next following nozzle14. At the moment the front part of weft 26 reaches the followingnozzle, the next escape outlet 18a is opened by means of opening 24 inthe rotary slide valve 22 (or the valves 28). Thus, the secondarycarrying pressure streams continuously passing through the succeedingnozzleto maintain the entraining of the front part of weft 26, while airthrough the preceding nozzle 14 is about to or has already stopped.Since the supply of secondary carrying pressure stream is alreadypartially or completely stopped due to the turning of slide valve 22 inthe distributor 19 (on action of valve 28), the major force and thus thecarrying force acts solely on the front end of the weft, stretching andattenuating the weft through the loom.

The action as specified above repeats steadily and thus weft 26 isgradually handed over and seriation from one nozzle 14 to the nextfollowing nozzle, etc. by the substantially longitudinally directed flowof the secondary carrying pressure stream until the weft reaches the endof the guiding channel 11 in the guiding comb 9. The oblique directionof nozzle 14 enhances the forward flow.

The spacing of the exits 18, the width of the bypassing opening 24 inthe rotary slide valve 22 of distributor l9 and the distance of nozzles14 along the guiding channel 11 of the guiding comb 9 are allsynchronized relative to each other to achieve a flow wave of thesecondary pressure stream congruent with the velocity of the front endpart of weft 26 so that only the front part of weft 26 is surrounded bythe flowing secondary carrying pressure fluid. Thereby, the maximumtraction effect of the secondary carrying pressure fluid is concentratedat the front part of weft 26 and it is pulled during the whole pickingcourse by its front part, being straightened and attenuated during itsentire run through shed 13. After picking weft 26 through shed 13,further weaving phases are carried on in the currently known manner.Reed 7 beats up weft 26 to the fabric, is cut off and the batten 1 isreturned to the picking position, whereupon the whole cycle isrepeatedfor the next weft.

The coordination of the correct inlet of air through the nozzle 14 (andsuccessive similar nozzles) into channel 11 with the picking of the weftthrough the channel so that the maximum driving effect acts always uponthe front part of weft 26 can be achieved by monitoring the picking ofthe front part of weft 26 by the system shown in FIG. 4. The photocell,a pneumatic sensor, a capacitory sensor or other sensor 27, etc. whichemits a signal upon the picking of the front end may be transformed andamplified to control the valves in order to admit air into the nozzlesat that moment, at which weft 26 runs with its front end beside theappropriate nozzle.

It will thus be seen that according to the present invention the weftthread need only be thrown through a portion of the shed by the primarypicking means (be it pneumatic, roller or other means). The rest of thethrow or pick is effected by the action of the successively actuatedflow streams on the front end of the weft. Thus, the front end of weftis always under the influence of a pressurized entraining fluid whichhas greater force or velocity than the flow streams acting on any otherpart of the weft. The valve distributor system of FIGS. 2 and 3 and thesensor-valve controlsystem of FIG. 4 insure an efficient, selective andpredetermined flow stream at the front end of the weft wheneverrequired. To insure, further, a stream of air sufficient to carry theweft thread and/or to overcome any drag, the nozzles 14 may be varied insize, the valve openings 18 may be varied in size and/or the pressureregulated by increasing or decreasing pressurizing means so that theflow along channel 11 is regulated.

The advantage of the instant method of picking weft resides in the factthat the weft is pulled by its front end during the entire time of itstravel through shed 13 and thus cannot form loops or waves; nor can itbe caught up by warp 12 or by the plate of guiding comb 9. This results,consequently, in a higher quality of fabric. A further advantage residesin the fact that weft threads can be carried through greater distancesand larger widths since the driving effect of the secondary carryingpressure fluid upon the weft lasts for the entire time it moves throughshed 13. Moreover, the picking velocity is also faster in comparison toconventional picking methods since the velocity of the driving flow ofthe secondary carrying pressure fluid does not diminish during the wholetime and length of weft picking.

The increase of picking width and picking velocity results in increasedefficiency of the weaving machine. The successive supply of thesecondary carrying pressure fluid to the separate nozzles such as nozzle14 is advantageous since it accomplishes the supply of needed fluidwhich is not so in hitherto known methods, or by the continuous supplyof carryingpressure fluid simultaneously to all nozzles 14.

Numerous other advantages of the method and apparatus of this inventionmay be made without departing from the spirit and scope of thisinvention. Accordingly, it is to be understood that the invention is notto be limited to the disclosed embodiments thereof except as defined inthe appended claims.

What is claimed is:

l. A method for inserting weft threads through the shed formed on ashuttleless loom comprising the steps of contacting a weft of threadwith means for picking up and carrying said weft thread through at leastpart of the length of the shed in a substantially longitudinal directionand subsequently serially contacting the front part of the weft threadwith pressure fluid flow streams, selectively controlling the serialflow streams to convey the weft thread in a selectively controlled anddirected manner in a substantially longitudinal direction through theremaining portion of the length of the shed.

2. The method as defined in claim 1 wherein the weft thread is initiallypicked up and carried through at least part of the length of the shed bya primary pressure I 3. The method as defined in claim 1 wherein theweft thread is initially picked up and carried through at least part ofthe length of the shed by rotating feeding rollers.

4. The method as defined in claim 1 wherein the weft thread is carriedinto a guiding channel formed by a comb having a plurality of plates andopenings and which is periodically immerged into the shed.

5. The method as defined in claim 4 including means for regulating thepressure of the flow of fluid along the longitudinal length of the shed.

6. The method as defined in claim 5 wherein the plurality of successive,pressure fluid flows are directed obliquely into the guiding channel ofthe guiding combs.

7. Apparatus for inserting weft threads in the shed formed on ashuttleless weaving loom having a batton comprising means for picking upand carrying a weft thread through at least part of the length of theshed, a comb having a plurality of plates supported on said batten, saidcomb forming a guiding channel for said weft thread upon beingperiodically inserted in said shed, a plurality of noule means supportedon said batten for directing a plurality of individual pressure fluidflows into said guiding channel, valve means connected to the nozzlemeans for activating and deactivating the individual nozzle means andmeans for successively controlling said valves to exert a fluid flow onthe leading end of said weft thread whereby said weft thread may bepulled from its leading end in a selectively controlled and directedmanner through said shed.

8. Apparatus as defined in claim 7 wherein the nozzle means fordirecting a plurality of pressure fluid flows into the guiding channelcomprises, a plurality of independent nozzles serially mounted on thebatten, each being directed obliquely into said guiding channel.

9. Apparatus as defined in claim 8 including sensing elements locatedadjacent the plates of the guiding comb to selectively controlactivation and deactivation of the nozzles.

10. Apparatus as defined in claim 9 including means for regulating thepressure in each of said nozzles.

11. Apparatus as defined in claim 7 wherein the valve means foractivating and deactivating the nozzle means for directing the pluralityof pressure fluid flows is a distributor connected to a source ofpressure fluid and connected through hoses to the nozzle means andincludes a rotary slide valve synchronized with the movement of the mainshaft of the shuttleless loom.

12. Apparatus as defined in claim 10 wherein the rotary slide valve isof a size sufficient to cover at least two exits to the hoses at thesame time.

1. A method for inserting weft threads through the shed formed on ashuttleless loom comprising the steps of contacting a weft of threadwith means for picking up and carrying said weft thread through at leastpart of the length of the shed in a substantially longitudinal directionand subsequently serially contacting the front part of the weft threadwith pressure fluid flow streams, selectively controlling the serialflow streams to convey the weft thread in a selectively controlled anddirected manner in a substantially longitudinal direction through theremaining portion of the length of the shed.
 2. The method as defined inclaim 1 wherein the weft thread is initially picked up and carriedthrough at least part of the length of the shed by a primary pressurefluid.
 3. The method as defined in claim 1 wherein the weft thread isinitially picked up and carried through at least part of the length ofthe shed by rotating feeding rollers.
 4. The method as defined in claim1 wherein the weft thread is carried into a guiding channel formed by acomb having a plurality of plates and openings and which is periodicallyimmerged into the shed.
 5. The method as defined in claim 4 includingmeans for regulating the pressure of the flow of fluid along thelongitudinal length of the shed.
 6. The method as defined in claim 5wherein the plurality of successive, pressure fluid flows are directedobliquely into the guiding channel of the guiding combs.
 7. Apparatusfor inserting weft threads in the shed formed on a shuttleless weavingloom having a batton comprising means for picking up and carrying a weftthread through at least part of the length of the shed, a comb having aplurality of plates supported on said batten, said comb forming aguiding channel for said weft thread upon being periodically inserted insaid shed, a plurality of nozzle means supported on said batten fordirecting a plurality of individual pressure fluid flows into saidguiding channel, valve means connected to the nozzle means foractivating and deactivating the individual nozzle means and means forsuccessively controlling said valves to exert a fluid flow on theleading end of said weft thread whereby said weft thread may be pulledfrom its leading end in a selectively controlled and directed mannerthrough said shed.
 8. Apparatus as defined in claim 7 wherein the nozzlemeans for directing a plurality of pressure fluid flows into the guidingchannel comprises, a plurality of independent nozzles serially mountedon the batten, each being directed obliquely into said guiding channel.9. Apparatus as defined in claim 8 including sensing elements locatedadjacent the plates of the guiding comb to selectively controlactivation and deactivation of the nozzles.
 10. Apparatus as defined inclaim 9 including means for regulating the pressure in each of saidnozzles.
 11. Apparatus as defined in claim 7 wherein the valve means foractivating and deactivating the nozzle means for directing the pluralityof pressure fluid flows is a distributor connected to a source ofpressure fluid and connected through hoses to the nozzle means andincludes a rotary slide valve synchronized with the movement of the mainshaft of the shuttleless loom.
 12. Apparatus as defined in claim 10wherein the rotary sLide valve is of a size sufficient to cover at leasttwo exits to the hoses at the same time.